Device for measuring the depth of a groove between the ribs of the tread of a vehicle tire to determine the amount of wear of such ribs



Nov. 14, 1967 A. MAZEIKA 3,352,018

DEVICE FOR MEASURING THE DEPTH OF A GROOVE BETWEEN THE RIBS OF THE TREAD OF A VEHICLE TIRE TO DETERMINE THE AMOUNT OF WEAR OF SUCH RIBS Filed May 6, 1965 pan c-1242M E IN VE N TOR. Awe/ET MAZE/KA United States Patent Office 3,352,018 PatentedNov. 14, 1967 3,352,018 DEVICE FOR MEASURING THE DEPTH OF A GROOVE BETWEEN THE RIBS OF THE TREAD OF A VEHICLE TIRE T DETER- MINE THE AMOUNT OF WEAR OF SUCH RIBS Albert Mazeika, Chicago, IlL, assignor to Milton Manufacturing Company, Inc., Chicago, Ill., a corporation of Illinois Filed May 6, 1965, Ser. No. 453,778 2 Claims. (Cl. 33-169) One of the objects of the invention is to provide a dcviceof this character in which there is provided a bridging foot pivotally arranged in a novel construction so as to flatly engage the surface of adjacent ribs defining a groove into which a probing pin is adapted to be projected to accurately indicate through an indicia-bearing member the amount of tire wear that has been occasioned by the use of the tire.

Another and equally important object of the invention is to provide a device of the character hereinafter described in which the bridging foot may be pivoted into a side-by-side or parallel position with respect to the member carrying the same to provide a compact device which may be conveniently carried in the pocket of the user.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

FIG. 1 is a side elevational view of the invention in its collapsed condition;

FIG. 2 is a perspective view of the invention in its extended position;

FIG. 3 is a side elevational view of the invention showing the same in applied position;

FIG. 4 is a longitudinal sectional detailed view of the invention taken substantially on line 44 of FIG. 2.

The preferred form of construction of my invention comprises an elongated bridging foot which, when the device is in operative position, will bridge grooves 11 of various widths between the ribs 12 of the tread 13 of a tire 14'.

The bridging foot in transverse section is channelshaped providing a bottom wall 14 and opposite parallel walls 15. The walls 15 are provided with diagonally extending elongated slots 16. Projecting through these slots 16 are pins 17 carried on opposite sides of a tube or sleeve 18 in alignment with a transverse axis adjacent the lower end portion of the latter.

The slots 16 and the pins 17 provide a pivotal connection between the bridging foot and the sleeve 18 whereby the sleeve 18 may be moved a predetermined distance from the bridging foot to position the latter in a position to be pivoted about the pins 17 into side-by-side or parallel relation with respect to the sleeve 18 as shown in FIG. 1. When the pins 17 are disposed in their lowermost position in the diagonal slots 16, the lower end portion 19 of the sleeve 18 will have bearing engagement with the wall 14 of the bridging plate 10. Such an arrangement results in maintaining the bridging plate 10 in a substantial right-angular position with respect to the long axis of the sleeve 18.

Formed in the wall 14 is an opening 20 through which a probing pin 21 is adapted to be projected. This probing pin 21 is fixed to and carried by a plunger 22 in any suitable manner. The plunger 22 may be tubular or a solid rod, and is slidably and frictionally arranged in the sleeve 18. The plunger has printed or stamped thereon indicia 23 in the direction of its longitudinal length and each indicative of of an inch.

Carried by the lower end 24 of the plunger 22 is a coil spring 25 or other friction means which is movable with the plunger 22 and engages the inner surface of the sleeve 18 to hold the plunger in an adjusted position relative to the sleeve in which position it has been disposed by engagement of the probing pin 21 with the bottom 26 of the groove 11.

To complete the invention, I attach to the sleeve 18 a spring clip 27 which may be utilized to clip the device to the pocket when the device is collapsed in the position shown in FIG. 1.

The outer end portion 28 of the plunger may be knurled as at 29 to provide a firm finger gripping of the plunger.

To collapse the device in the condition shown in FIG. 1, the plunger 22 is moved longitudinally of the sleeve 18 a distance sufficiently to withdraw the probing pin from the opening 20. The sleeve 18 is then moved in a direction away from the bridging foot to dispose the lower end portion of the sleeve a sufiicient distance from engagement with the wall 14 in which position the bridging foot may then be pivoted axially about the pins 17 into a sideby-side or parallel position with respect to the sleeve 18.

When in use in the manner shown in FIG. 3, the probing pin will extend into the groove 11 and engage the bottom thereof and by referring to the indicia 23, the user may determine the amount of tread wear that has been occasioned by the use of the tire.

My device is especially useful for determining the wear of the tread of tires having relatively wide grooves and the measurement of such wear will be substantially accurate by reason of the fact that the tube 18 by its engagement with the wall 14 of the probing foot, will maintain the bridging plate in a position substantially at right angles with the long axis of the sleeve 18.

Knowing the depth of the grooves between the ribs of the tread of the tire, the amount of wear of the tread may be quickly determined from a reading of the indicia 23. If the ribs of the tire tread have worn, the gauge plunger 22 will by the indicia indicate in thirty-seconds of an inch the amount of such wear. Then by comparing the depth of the groove as registered by the gauge plunger, with the known original depth of the groove before use, the result will be a determination of how much the tread has been worn by use.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. 1, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. A device for measuring the depth of the groove between the ribs of the tread of a vehicle tire to determine the amount of wear of such ribs, comprising (a) an elongated bridging member adapted to bridge the groove between the ribs of the tread of the tire and flatly engage the surface of such ribs,

(b) a tubular service,

(c) an indicia-bearing plunger slidably positioned in the sleeve,

(d) a probing pin carried by and extending from one end of said plunger and movable therewith,

(e) said bridging member having an opening centrally located between its opposite end portions through which said pin may be projected by movement of the plunger in a direction to project said probing pin into said groove,

(f) means providing pivotal connection between said bridging member and said sleeve to pivotally support said bridging member for movement about a trans verse axis with respect to said sleeve when said probing' pin is in withdrawn position from said groove and said opening by longitudinal movement of said plunger in an opposite direction to free said bridging member for pivotal movement about said transverse axis in-to substantial parallel relation with respect to the long axis of said sleeve, and

(g) friction means carried by said plunger and movable therewith and engaging the inner surface of said sleeve to hold said plunger in an adjusted position relative to said sleeve,

(h) said means for pivotally connecting said bridging member to said sleeve comprising opposite diagonal slots formed in opposite walls of said bridging membet and pivot pins carried by said sleeve and projecting into said slots.

2. A device for measuring the depth of the groove between the ribs of the tread of a vehicle tire to determine the amount of wear of such ribs, comprising (a) an elongated groove spanning foot adapted to bridge said groove and flatly engage the surface of adjacent ribs defining such groove,

(b) a tubular sleeve,

() an indicia-bearing plunger slidably and frictionally positioned in the sleeve,

(cl) a probing pin carried by and extending from one end of said plunger and movable therewith,

(c) said foot having an opening centrally located between its opposite end portions through which said pin may be projected by movement of the plunger within said tubular member in a direction to project said probing pin into said groove, and

(f) means providing pivotal connection between said foot and said sleeve to pivotally support said foot for movement about a transverse axis with respect to said sleeve when said probing pin is in withdrawn position from said groove and said opening by longitudinal movement of said plunger in an opposite direction to free said foot for pivotal movement about said transverse axis into substantial parallel relation with respect to the long axis of said sleeve,

(g) said means for pivotally connecting said bridging member to said sleeve comprising opposite diagonal slots formed in opposite walls of said bridging member and pivot pins carried by said sleeve and projecting into said slots.

References Cited UNITED STATES PATENTS 1,679,473 8/1928 Kabisius 33-169 2,619,727 12/1952 Krohn 33-169 X 3,171,278 3/1965 Howard 33-169 X 3,277,905 10/1966 Thompson 33-l69 X ROBERT B. HULL, Primary Examiner. 

1. A DEVICE FOR MEASURING THE DEPTH OF THE GROOVE BETWEEN THE RIBS OF THE TREAD OF A VEHICLE TIRE TO DETERMINE THE AMOUNT OF THE WEAR OF SUCH RIBS, COMPRISING (A) AN ELONGATED BRIDGING MEMBER ADAPTED TO BRIDGE THE GROOVE BETWEEN THE RIBS OF THE TREAD OF THE TIRE AND FLATLY ENGAGE THE SURFACE OF SUCH RIBS, (B) A TUBULAR SERVICE, (C) AN INDICIA-BEARING PLUNGER SLIDABLY POSITIONED IN THE SLEEVE, (D) A PROBING PIN CARRIED BY AND EXTENDING FROM ONE END OF SAID PLUNGER AND MOVABLE THEREWITH, (E) SAID BRIDGING MEMBER HAVING AN OPENING CENTRALLY LOCATED BETWEEN ITS OPPOSITE END PORTIONS THROUGH WHICH SAID PIN MAY BE PROJECTED BY MOVEMENT OF THE PLUNGER IN A DIRECTION TO PROJECT SAID PROBING PIN INTO SAID GROOVE, (F) MEANS PROVIDING PIVOTAL CONNECTION BETWEEN SAID BRIDGING MEMBER AND SAID SLEEVE TO PIVOTALLY SUPPORT SAID BRIDGING MEMBER FOR MOVEMENT ABOUT A TRANSVERSE AXIS WITH RESPECT TO SAID SLEEVE WHEN SAID PROBING PIN IS IN WITHDRAWN POSITION FROM SAID GROOVE AND SAID OPENING BY LONGITUDINALLY MOVEMENT OF SAID PLUNGER IN AN OPPOSITE DIRECTION TO FREE SAID BRIDGING MEMBER FOR PIVOTAL MOVEMENT ABOUT SAID TRANSVERSE AXIS INTO SUBSTANTIAL PARALLEL RELATION WITH RESPECT TO THE LONG AXIS OF SAID SLEEVE, AND (G) FRICTION MEANS CARRIED BY SAID PLUNGER AND MOVABLE THEREWITH AND ENGAGING THE INNER SURFACE OF SAID SLEEVE TO HOLD SAID PLUNGER IN AN ADJUSTED POSITION RELATIVE TO SAID SLEEVE, (G) FRICTION MEANS CARRIED BY SAID PLUNGER AND MOVMEMBER TO SAID SLEEVE COMPRISING OPPOSITE DIAGONAL SLOTS FORMED IN OPPOSITE WALLS OF SAID BRIDGING MEMBER AND PIVOT PINS CARRIED BY SAID SLEEVE AND PROJECTING INTO SAID SLOTS. 